Be it known that I, James S. Finn, a citizen of United States, residing at 2413 Woodview Drive, Huntsville, Ala. 35801 have invented a new and useful xe2x80x9cSystem And Method For Controlling Air Bag Deployment Systems.xe2x80x9d
The present invention relates generally to a system and method for controlling air bag deployment systems. More particularly, the present invention provides a system and method for controlling air bag deployment systems based on the presence, position, size, and weight of persons for which the air bag deployment system is designed to protect.
Safety restraint systems which self-actuate from an undeployed to a deployed state without the need for intervention by the operator, i.e., xe2x80x9cpassive restraint systems,xe2x80x9d and particularly those restraint systems incorporating inflatable bags or cushions, as well as the use of such systems in motor vehicles have gained general appreciation.
It is well known that a vehicle occupant may be protected using a cushion or bag that is inflated with gas, e.g., an xe2x80x9cair bagxe2x80x9d, when the vehicle encounters sudden deceleration, such as in a collision. During deployment, the rapidly evolving gas with which the bag is typically filled is an inert gas, e.g., nitrogen. In such systems, the air bag is normally housed in an uninflated and folded condition to minimize space requirements. In an emergency, gas is discharged from an inflator to rapidly inflate the air bag. The air bag, upon inflation, serves to restrain the movement of the vehicle occupant as the collision proceeds. In general, such air bags are commonly designed to be inflated in no more than a few milliseconds.
Vehicular inflatable restraint systems generally include multiple crash sensors positioned about or mounted to the frame and/or body of the subject vehicle and serve to sense sudden decelerations by the vehicle. In turn, the sensor sends a signal to an air bag module or assembly strategically positioned within the riding compartment of the vehicle to actuate deployment of the air bag. In general, an air bag provided for the protection of a vehicle driver, i.e., a driver side air bag, is mounted in a storage compartment located in the steering column of the vehicle. An air bag for the protection of a front seat passenger, i.e., a passenger side air bag, is typically mounted in the instrument panel/dash board of the vehicle.
Typical air bag restraint systems make use of an air bag module that generally includes an outer reaction housing or canister, commonly referred to as a xe2x80x9creaction canxe2x80x9d or, more briefly, as a xe2x80x9ccanxe2x80x9d. The reaction canister generally serves to support or contain other components of the air bag module system, including what is referred to as a xe2x80x9cair bag inflatorxe2x80x9d or, more briefly, as an xe2x80x9cinflatorxe2x80x9d, or, alternatively, as a xe2x80x9cgeneratorxe2x80x9d. The inflator, upon actuation, acts to provide the gas to inflate the air bag.
Inflators used in such systems are typically either of a pyrotechnic or hybrid type. Pyrotechnic inflators generally contain a gas generating material, which upon activation generates gas used to inflate the air bag. In general, the inflation gas produced by a pyrotechnic inflator is emitted from openings or emission ports along the length of the inflator.
In contrast, hybrid inflators, in addition to a body of ignitable pyrotechnic material, generally contain as the primary inflation gas a stored, compressed gas which, upon proper actuation, is expelled from the inflator. As a consequence of the physics associated with the storage of compressed gases, the container used to store this compressed gas typically has a cylindrical shape. Furthermore, the discharge of gas from such a cylindrically shaped gas storage container typically occurs by way of openings or emission ports at only one end of the cylindrical container.
It is generally desired that the air bag attain a straight or a non-skewed geometry upon deployment, particularly where the air bag module assembly is for installation mid-mount within a vehicle dashboard or panel, that is in a central region of the vehicle dashboard or panel, between the upper and lower portions thereof and for which the direction of the bag deployment towards the vehicle occupant is generally perpendicular. Such an installation is commonly referred to as a xe2x80x9cmid-mount installation.xe2x80x9d
To that end, it is generally desired that the emission of gas into the air bag from such a storage container be done in a fairly uniform manner. With typical air bag/inflator assemblies, such uniform emission is generally attained by having a relatively even emission of gas into the deploying bag along the length of the gas inlet opening of the air bag connected, directly or indirectly, to the inflator. In this way the bag is properly uniformly deployed and the risk of the bag deploying in a skewed manner due to the discharge of gas from only one end of the storage container is avoided.
As mentioned above, airbags have proven to be effective in preventing injury resulting from head-on and near head-on collisions, when used correctly in conjunction with the shoulder-lap restraints. However, a small number of highly publicized incidents have highlighted a serious risk of potentially catastrophic injury to small adults, children, or infants in rear-facing child-safety seats. While it is certainly advisable to place small children or infants occupying rear-facing child-safety seats in a rear seat, in certain types of vehicles, namely pick-up trucks, this is simply not an option.
As a result, a demand has arisen for selective deployment of the automobile""s self-inflating restraint. In response, certain automobile manufacturers now provide a key-switch to allow the owner/operator to choose whether or not the self-inflating restraint should be xe2x80x9carmedxe2x80x9d that is to say, whether the self-inflating restraint should be active and deployable in the event of a collision. However, these types of manual controls, or overrides, also carry an inherent risk: the inadvertent failure to re-arm the restraint for an adult passenger, or the failure to deactivate the restraint in the event that the passenger seat is occupied by a child or safety seat. Further, the state of the art airbag deployment system does not detect whether the passenger seat is unoccupied and in the event of a collision fires the airbag, needlessly resulting in the unnecessary expense of replacing the dash and airbag mechanism.
Smart systems now being tested include seat antennas that monitor changes in electric fields; child seats with built-in detectors, and ultrasonic sensors similar to submarine sonar. However, none of these technologies have proven to be as useful as needed and are very costly to implement. Furthermore, these systems are very inaccurate and therefore can only provide a gross approximation of the size of the occupant.
What is needed, then, is a device that can ascertain the presence, position, size, and weight of the vehicle occupants and either deactivate the air bag system in response to small adults or children or to adjust the inflation rate of the airbag.
It is therefore an object of the present invention to provide a novel method and apparatus for controlling air bag deployment systems.
Another object is to provide a means for determining the presence of the occupants for which the air bag system is designed and a means for controlling the air bag system based on the presence of the occupants.
A further object of the present invention is to provide a means for determining the position of the occupants relative to the air bag system and a means for controlling the air bag system based on the position of the occupants.
Another object of the present invention is to provide a means for determining the size of the occupants for which the air bag system is designed and a means for controlling the air bag system based on the size of the occupants.
Still another object is to provide a means for determining the weight of the occupants relative to the air bag system and a means for controlling the air bag system based on the weight of the occupants.
Yet another object is to provide a means for determining the presence of a child safety seat and a means for controlling the air bag system based on the presence of the child safety seat.
These and other objects are provided, according to the present invention, by a system and method for controlling air bag deployment systems including an impulse radio radar to determine the presence, position, size, and weight of the occupants for which the air bag system is designed to detect and for interfacing the information relating to presence, position, size, and weight of the occupant with a variable rate airbag deployment means or an airbag deactivation means.